UNIT VI LEARNING OBJECTIVES – General & Special Senses: LECTURE

Senses I – General senses

1. Differentiate between the processes of sensation and perception. Identify where each process occurs, including the structures involved.
2. Describe the general structure and function of sensory receptors. Classify sensory receptors based on their structure, function, location, and stimuli received.
3. List the four general types of stimuli that can trigger depolarization in sensory receptors.
4. Predict the relative speed of impulse transmission based on the type of nerve fiber (e.g., myelinated vs not, large vs small axon diameter).
5. List and describe the five general senses. For each, identify the type of stimuli received, the type of sensory receptors involved, and the sensations perceived by the animal.
6. Differentiate between superficial (external) and central (internal) thermoreceptors.
7. Explain the process of thermoregulation and the role of the hypothalamus. Explain how anesthesia affects an animal’s metabolism and ability to thermoregulate.
8. Describe what pain is and explain its adaptive benefits. Compare and contrast the different types of pains. Explain the difference between pain threshold and pain tolerance.
9. Describe the structure and function of nociceptors, comparing and contrasting them to other sensory receptors.
10. Describe the steps of nociception. Explain the phenomenon of windup as it relates to modulation. Explain how windup can be reduced or eliminated in patients.
11. List various measures used to assess pain in animals. Identify which are considered objective vs subjective measurements.
12. Compare the effect of analgesic vs an anesthetic (local and general) on an animal in terms of sensation and/or perception.

Senses II – Special senses: taste, olfaction, hearing, balance

Describe the structure (macro and micro) and location of taste buds. Identify locations of other chemoreceptors involved in gustation (taste).

Explain why identification of bitter-tasting substances is important for herbivores.

Describe the structure (macro and micro) and location of olfactory receptors, bulb, and CN I.

Describe what a pheromone is and explain the role of pheromones in animal communication. Provide examples.

Identify the location and function of the parts of the ear (i.e., external, middle, and inner).

Describe the path of sound waves from the external environment, through various structures, to the cochlea. Describe the structures and processes involved to convert sound waves into auditory impulses.

Describe otitis, including what causes it, predisposing factors, how diagnosed. Explain how otitis can lead to aural hematomas.

Describe the structures and processes that contribute to the sense of balance. Compare and contrast these structures to those involved in the sense of hearing.

Describe the conditions that lead to motion sickness.

Senses III – Special senses: vision

1. Identify the location and function of the parts of the ear (internal and external), including the three layers and two fluid-filled compartments. Identify pathologies associated with specific structures.
2. Describe the process of accommodation and the structures involved.
3. Describe the path of light through the eye (identifying each structure) to the retina.
4. Compare and contrast rods and cones in terms of their structure, location (species found), and function (sensitivity to….).
5. Contrast the optic disc, fovea centralis, tapetum lucidum in terms of structure, function, and location in the eye and species found.
6. Describe the production and removal of aqueous humor, including structures involved. Relate this to glaucoma.
7. Identify extraocular structures and their function. Identify pathologies associated with specific structures.
8. Name and describe the lacrimal structures involved in tear production and drainage. Identify tests used to determine if production and drainage are functioning properly.
9. Describe the following eye-related disorders: ulcerative keratitis (corneal ulcers), equine recurrent uveitis (moonblindness), glaucoma, cataracts, nuclear sclerosis, palpebral problems, conjunctivitis (including KCS). Description can include species primarily affected, structures involved, possible causes, signs, diagnostic tests, complications, and treatment.

Lab 8 – Special Senses – Eye & Ear

Identify parts of the ear and eye using models and preserved specimens (eye only). Understand the function of each structure. Identify structures that have disorders commonly associated with them (e.g, corneal ulcers due to entropion).

State the purpose, materials needed, and steps to perform a Schirmer tear test and fluorescein dye test. Note which of the two tests to perform first and why.